1. Field of the invention
This invention concerns a mechanical torque coupling structure, in general. More specifically, it relates to a heavy duty torque-shaft coupling unit that is employed to transfer torque energies laterally with respect to the axis of the torque shaft.
2. Description of the Prior Art
In connection with oil-well drilling and similar activities, there is a continuing need for a heavy-duty and yet sensitive dynamic torque meter. While a torque meter coupling structure has been proposed in my earlier U.S. Pat. No. 3,823,607, issued July 16, 1974, that structure makes use of a sleeve to create the required deflection for measuring the torque and consequently it requires considerable longitudinal space relative to the axis of the shaft involved. Since that time, and in view of the development of a more sensitive system for measuring deflection of torque elements such as disclosed in the U.S. patents assigned to the same assignee as this application, i.e. U.S. Pat. Nos. 4,122,709 and 4,136,559, it has been discovered that a structure with greatly shortened longitudinal dimension could be employed.
Thus it is an object of this invention to provide a heavy-duty large torque deflection unit that is applicable to the torque measurement of a chain-drive deep-well rotary hook up.